Bump wpreadme2markdown/wp2md from 3.0.3 to 4.0.2

Bumps [wpreadme2markdown/wp2md](https://github.com/wpreadme2markdown/wp2md) from 3.0.3 to 4.0.2.
- [Release notes](https://github.com/wpreadme2markdown/wp2md/releases)
- [Changelog](https://github.com/wpreadme2markdown/wp2md/blob/master/CHANGELOG.md)
- [Commits](https://github.com/wpreadme2markdown/wp2md/compare/3.0.3...4.0.2)

---
updated-dependencies:
- dependency-name: wpreadme2markdown/wp2md
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

composer.json

@@ -33,7 +33,7 @@
 	},
 	"require-dev": {
 		"pressbooks/coding-standards": "^1.1",
-		"wpreadme2markdown/wp2md": "^3.0",
+		"wpreadme2markdown/wp2md": "^4.0",
 		"yoast/phpunit-polyfills": "^1.0.1"
 	},
 	"scripts": {